Renewable electric fuse



Aug. 18, 1925.

S. B. CONDIT, JR

RENEWABLE ELECTRIC FUSE Filed Juno '7, 1.919

Patented Aug. 18, 1925.

UNITED STATES PATENT OFFICE.

SEAR/S B. CONDIT, JR, OF BROOKLINE, .IVEASSACHUSETTS, ASSIGNOR TO CONDIT ELEC- TRIGAL MANUFACTURING COMPANY, OF SOUTH BOSTON, MASSACHUSETTS, A COR- PORATION OF MASSACHUSETTS.

RENEYVABLE ELECTRIC FUSE.

Application filed June 7, 1919.

To all whom it may concern:

Be it known that 1, Same B Czarnu'r, Clix. a citizen of the United States. and resident of Brookline, in the county of Norfolk and State of Massachusetts, have invented an Improvement in Renewable Electric Fuses, of which the following is a specification.

My invention relates to a renewable electric fuse of the cartridge type and has for its object to provide a fuse of such type having a vent for the expulsion of heated gas formed upon the blowing of the fuse and the cooling of the gas during its expulsion whereby to prevent the discharge of a dangerous flame.

Certain features herein shown but not claimed are shown and claimed in my copending application Serial No. 302,516, filed June 7, 1919.

Fig. 1 is a side view, partly in section, of a renewable electric fuse .-mbodying my invention.

Fig. 2 is an end view of the fuse with the end-plug in place.

Fig. 3 is a view of the inner face of the end-plug illustrating the gas passages therein.

Fig. 4 is a section along lines 14 of Fig.

Fig. 5 is an end view of the fuse with the end-plug removed and illustrating the fusesupporting plate and the fuse-receiving slot therein.

As here shown, my invention is applied to the renewable electric fuse having the enclosing tubular enclosing casing 10 of fibre or other suitable insnlatingmaterial on the ends of which are permanently received the end-ferrules 11 which, at their end-portions, are interiorly-threaded as at 12. Each end ferrule is formed with the in wardly-extended flange 13 against which the end of the enclosing casing is designed to abut and which also serves as an abutment for the fuse-supporting plate.

The fuse-supporting plate comprises a disc 14:, usually of copper, of slightly less diameter than the inner diameter of the endferrule whereby it may be removably received therein, and has a non-axial or eccentric slot 15 therethrough extended from the edge thereof beyond and above the center of the disc and terminates near the op- Seri aI No. 302,517.

posite edge of the disc. Said slot is adapted to be about midway between the center of the disc and the edge, as illustrated in Fig. 1, and is adapted to receive the fusible element.

The fusible element comprises the fuse strip of fusible material extended through the enclosing casing 10 and has its end-portion received in the fuse-receiving slot 15 and the extended end-portion is refiexed over the outer face of said fuse-supporting disc to which it is adapted to be clamped by the end-plug. The slot 15 is adapted to be of greater cross-section than that portion of the fuse received therein whereby it forms a gas vent for the casing.

The fuse clamping means comprises a clamping plate or end plug as the relatively thick disc 16, preferably of copper, having a threaded peripheral portion 17 whereby it is removably received in the end-ferrule, and the outer face thereof is provided with a slot 18 in which a screw-driver or other suitable tool is adapted to be received to remove said plug from or secure it to the fuse.

An axial opening 19 is extended through said plug and, in the outer face thereof, may be enlarged, as indicated at 20. A slotor gas passage 21 is formed in the inner face of said plug and extends from said opening 19 therein to the periphery of the plug. Said plug is adapted to be screwed against the reflexed end of the fuse strip to thereby secure it in firm electrical engagement with the fuse-supporting plate and consequently with the end-ferrule.

It will be noted that the fuse strip is relatively broad and the refiexed end thereof occupies the central portion of the space 22 between the fuse-supporting plate and the end plug whereby said space is roughly in the form of an annular ring closely bounded by said plate and plug with which the fuse eceiving slot 15 communicates. The axial opening 19 in the end-plug is closed by the reflexed end of the fuse strip and the slot or passage 21 in the inner face of said plug 1 V (e 13- in said slot 91 :iin'l "i sa eh"; ooenmn l in Ui' lE l plii zx l1 iasszz i e iilier-etln'oilgli iis eii'eetion of low lS fll' e'elSfil many times; and 5 the gas is brought intimately in eonteet with, relatively eoli'l lembzilisti'zieiiingr heilies whereby iii is cooled and may he expelled from the fuse without flame.

1% is ohvioiis that inmliiiee m'i'm'nt enninls of my invention in which :i tortuous path and anolin means for the oncriish'i may he provided Without (lepziriing from the spirii of my in? ni'ion.

claim:

1. A i'enewehle electric use 01'? the cartriilge type comprising a tubular enclosine inej in eni wh te :17

the casino 'ith hi-"1e ens e'zis opening; fl ei'el'hi strip extended ihiie and a Few! Y-OLl I 1i strip :igeinsi n l-plate said ulznnpmgz Olaijfl heving aerial opening Face therethiong'h the it 1101' enrl 017 is elosed by (he i'efiexeil en-zl o f-iziip and a (LS iessiiee in ilis innei' lei from o1 ling toward The periphery of said plate to provide a vent passage from the fuse,

2. A ienewahle enclose-(l electric film, of

,nl l iisih e iezins, sziii'l enihplng having: an .q ni ;hei'eiihi'ongh lillil a pas? g0 W i'h szii l epeningg extended riiphei'y of viii i plug and consnimih. The space he'tii'een said fuse sup- 3)'7(" and Hg whereby e tortuous l'(' Vi(lQ(l {or the expulsion of gas U. renewable electric fuse of the can "g'e type comprising :i tllblllel' enelosii'ig enal i ei'l'iiles ez'urieil iihei'ehy, enil loosely received in said end ferrules eccent ic fuse-receiving slots therelihwnp ln 2i use sii'ip erzl'endeil through Sflifl fLiSinQ and. the slots in said plates and. the enns irelexed ever the onl'ei' faces of said plates. and pines i'e iovzihl received i th 1 said ferrules engaging the refle ml ends oi? said iuse sli'i said i lii having? :1: .l openings ihei'etln'oiie'h in 1 slots in (heninnei' feces ercl'eniliniay from sa d axial oneliinxzs [to i'heiiJ peripheries to we wide ens vents for the Fuse. 1

in "oesl'imony whereof. I have sigyneil my name to this specification.

SEARS B. CONDIT, J12. 

